Compound S-60 may be prepared by fermentation of a suitable nutrient medium with a hitherto undescribed organism. Based on extensive taxonomic studies, the organism has been designated to be a new species, Pseudomonas elodea. An unrestricted permanent deposit of an organism of this species employed in making our heteropolysaccharide was made with the American Type Culture Collection on Nov. 21, 1978, under Accession No. ATCC 31461.
Various classification keys for the genus Pseudomonas and the culture descriptions of Pseudomonas species are found in the 7th Edition of Bergey's Manual (Breed et al., (1957)) and the 8th Edition of Bergey's Manual (Doudoroff et al., (1974), as well as by other schools in various publications; Hugh and Gilardi, 1974, Pseudomonas, Manual of Clinical Microbiology, 2nd ed., Lennette et al., Eds., pp. 250-269. American Society for Microbiology, Washington, D.C.; Weaver et al., 1972, Identification of Unusual Pathogenic Gram-Negative Bacteria, E. O. King, Center for Disease Control, Atlanta; Iizuka et al., 1963, Attempt at Grouping the Genus Pseudomonas, J. Gen. Appl. Microbiology 9:73-82; and Hendric et al., 1966, Identification of Certain Pseudomonas Species, Identification Methods for Microbiologists, Part A, Gibbs et al., Eds., pp. 1-7, Academic Press, New York.
These keys and descriptions were searched for a Pseudomonas species having morphological and cultural characteristics similar to those of ATCC 31461. The following considerations make the assignment of a new Pseudomonas species justified and necessary.